Radial IceCube IC-1 Passive Balanced Line Isolator & Hum Eliminator (XLR)

Radial IceCube IC-1: Instant Hum and Buzz Removal for Any Balanced Line

The Radial IceCube IC-1 is a passive, transformer-based balanced line-level isolator that eliminates the hum and buzz caused by ground loops by inserting an isolation transformer directly into the signal path. Barely larger than a barrel adapter, it drops inline between any two line-level devices -- a mixer and a powered speaker, a crossover and a power amp -- using standard XLR connections, and it goes to work the instant signal passes through it. For the tech who has spent an hour chasing a mysterious buzz before a show, it turns a stressful troubleshooting session into a ten-second fix.

What Causes Ground-Loop Hum

A ground loop forms when two pieces of audio equipment are joined both by their audio cable and by separate paths to earth ground, creating a loop in which small voltage differences push a low-frequency current through the cable shield. That current shows up as the familiar 60-cycle hum and buzz, and it grows worse as cable runs get longer and as more devices share contaminated or distant power. Because the noise rides on the ground connection rather than on the audio itself, no amount of EQ or gain riding will remove it -- you have to break the electrical loop.

How the IceCube Breaks the Loop

Inside the IceCube is a custom-wound Eclipse isolation transformer that passes the audio magnetically from input to output while providing galvanic isolation, so there is no direct electrical connection to carry ground current across the link. A ground lift switch then lifts the pin-1 shield to sever the remaining path, quieting stubborn loops that transformer isolation alone does not fully resolve. The result is clean audio with the loop electrically broken rather than merely masked by a filter.

Full-Bandwidth Sound With Room for Hot Signals

The real marvel of the IceCube is how much performance is packed into its diminutive size. Its Eclipse transformer holds a linear 20Hz to 20kHz response within a dB, preserving the full audio spectrum -- including the deep low end where smaller transformers typically distort or roll off. With a clip level of 25dBu and a maximum input of 15dBu, it swallows hot professional output levels without adding distortion or phase shift, so isolating a signal never costs you fidelity.

Where the IceCube Earns Its Keep

The IceCube is the problem-solver every AV technician and audio engineer should keep in the toolbox. Insert one on each side of a stereo pair to isolate a DJ mixer from the main PA, drop one between a crossover and a power amp to silence a rack, or use it to tame the noise that appears when a console feeds a distant powered speaker across a contaminated ground. Balanced and unbalanced devices both benefit, and plug-and-play operation means anyone on the crew can deploy it. When a buzz appears minutes before doors open, the IceCube is the fastest way to make it disappear.